Synnefo » snf-ganeti

def LockedMethod(fn):

  """Synchronized object access decorator.

  This decorator is intended to protect access to an object using the

  object's own lock which is hardcoded to '_lock'.

  """

  def _LockDebug(*args, **kwargs):

    if debug_locks:

      logging.debug(*args, **kwargs)

  def wrapper(self, *args, **kwargs):

    # pylint: disable-msg=W0212

    assert hasattr(self, '_lock')

    lock = self._lock

    _LockDebug("Waiting for %s", lock)

    lock.acquire()

    try:

      _LockDebug("Acquired %s", lock)

      result = fn(self, *args, **kwargs)

    finally:

      _LockDebug("Releasing %s", lock)

      lock.release()

      _LockDebug("Released %s", lock)

    return result

  return wrapper